It has been common practice for many years to package meat products in flat trays formed by molding techniques. These may be formed of paper pulp by flowing a water suspension of fibers onto a screen and drawing suction on the side of the screen remote from supply of the pulp, causing the fibers to mat in a more or less uniform thickness following the contours of the screen.
More recently, trays of similar form have been prepared by thermoforming a sheet of foamed thermoplastic resin, typically polystyrene.
In either event, the trays have been constituted by a flat, generally rectangular bottom and outwardly flared side walls of modest height. A usual meat tray will have a depth of about one-half inch, measured vertically from the upper edge of the side walls to the bottom inner surface. Such trays are generally satisfactory for packaging of single pieces of meat placed on trays and overwrapped, as with transparent shrink film.
These shallow trays, for lack of anything more suitable are also employed in preparing a package of many meat pieces; for example dismembered chicken parts, cubes of stew beef and the like. In such multiple piece packages, the sides of the packaged product are provided primarily by the overwrap. These packages are clumsy to prepare, awkward to store and tricky to unwrap.